1. Field of the Invention
The present invention relates to a method of fabricating a light-emitting element, in which less stress is applied to the light-emitting element.
2. Description of the Related Art
Light-emitting elements, such as light-emitting diodes (LEDs), emit light when electrons combine with holes. Light-emitting elements consume low power, have a long life, can be installed in a limited space, and are resistant to vibrations.
Light-emitting elements are classified into vertical type light-emitting elements, lateral type light-emitting elements, flipchip type light-emitting elements, and the like.
Of the above light-emitting elements, the vertical type light-emitting elements are being widely used since they can be reduced in size and have superior current diffusion properties. For example, a vertical light-emitting element may include a light-emitting structure in which a gallium nitride (GaN) pattern of an n type, a light-emitting pattern, and a GaN pattern of a p type are stacked. Light is generated in the light-emitting pattern when carriers (e.g., electrons) of the n-type GaN pattern combine with carriers (e.g., holes) of the p-type GaN pattern.
It is difficult as well as expensive to implement a substrate made of GaN series. Therefore, a heterogeneous substrate may be formed of GaN and a material different from GaN, such as silicon (Si), sapphire, or silicon carbide (SiC). Then, a light-emitting structure may be formed on the heterogeneous substrate, and the heterogeneous substrate may be removed from the light-emitting structure to complete a light-emitting element. This method of fabricating a light-emitting element is now being researched.
A substrate may be removed from a light-emitting structure by a lift-off method such as a chemical lift-off (CLO) method or a laser lift-off (LLO) method.
However, when the CLO method is used, a sacrificial layer interposed between the substrate and the light-emitting structure may cause stress on the light-emitting structure. Since the LLO method uses a high-power laser beam, stress may be applied to (for example, cracks may be created in) the light-emitting structure when the LLO method is used.